WEBVTT - BrainStuff Classics: What Is Red Snow? 0:00:01.920 --> 0:00:06.480 Welcome to brain Stuff production of I Heart Radio. Hey 0:00:06.519 --> 0:00:09.280 brain Stuff, Lauren Bogle bom here with a classic episode 0:00:09.320 --> 0:00:12.680 for you today about the strange phenomenon of red snow, 0:00:13.240 --> 0:00:18.200 also called watermelon snow, pink snow, or blood snow. This 0:00:18.320 --> 0:00:21.520 is a phenomenon where snow appears pink to red in 0:00:21.760 --> 0:00:25.120 streaks and patches due to the growth of a species 0:00:25.160 --> 0:00:29.760 of algae, and aside from being visually striking, it's actually 0:00:29.760 --> 0:00:35.680 fairly concerning. Hey brain Stuff, Lauren Bogle bomb here. Normally 0:00:36.040 --> 0:00:39.360 snow looks white. This is because the ice crystals that 0:00:39.440 --> 0:00:42.280 make up clusters of snow reflect and scatter every color 0:00:42.320 --> 0:00:46.000 frequency in the visible light spectrum. So when sunlight bounces 0:00:46.000 --> 0:00:48.400 off of a snow bank, all those colors blend together, 0:00:48.600 --> 0:00:52.040 giving the snow a white appearance, or at least that's 0:00:52.080 --> 0:00:55.640 what usually happens. Every so often, though mother Nature throws 0:00:55.680 --> 0:00:58.320 us a curveball with a blanket of non white snow. 0:00:59.320 --> 0:01:01.480 Plenty of the ld Or was a Roman naturalist who 0:01:01.520 --> 0:01:04.880 lived from twenty three to seventy nine. In one of 0:01:04.920 --> 0:01:07.880 his books, he wrote about red tinted snow, which ancient 0:01:07.920 --> 0:01:12.039 travelers sometimes encountered. His hypothesis was that snow changes color 0:01:12.080 --> 0:01:14.520 as time goes by, like a rusting piece of iron 0:01:14.920 --> 0:01:19.800 snow itself. Plenty wrote Reddens with old age, and reports 0:01:19.800 --> 0:01:22.080 of crimson colored snow kept pouring in over the next 0:01:22.120 --> 0:01:25.000 to millennia. To figure out what's really going on, we 0:01:25.040 --> 0:01:28.800 spoke via email with climate scientist Randall's Serveny. He reports 0:01:29.120 --> 0:01:31.479 people in the dark and Middle Ages were often freaked 0:01:31.480 --> 0:01:34.880 out by it. A professor at Arizona State University, Serveny 0:01:34.959 --> 0:01:37.640 dedicated an entire book to weird weather stories in two 0:01:37.680 --> 0:01:41.000 thousand five, titled Freaks of the Storm. It includes a 0:01:41.000 --> 0:01:44.839 passage on red snow. As Serveny points out, there Charles 0:01:44.920 --> 0:01:47.520 Darwin himself once came across white snow in the Andes 0:01:47.520 --> 0:01:50.800 Mountains that turned blood red as it thawed. Another important 0:01:50.800 --> 0:01:53.960 figure who witnessed the tinted precipitation was Sir John Ross, 0:01:54.000 --> 0:01:57.760 a British naval officer and Arctic explorer. A reddish or 0:01:57.800 --> 0:02:00.880 pinkish snow isn't just a historical curiosit city it's still 0:02:00.920 --> 0:02:04.800 being observed. In February, for instance, a puddle of red 0:02:04.840 --> 0:02:08.079 water that turned out to be melted vermillion snow was 0:02:08.120 --> 0:02:12.720 found in Glacier National Park, So what's the mechanism behind this? 0:02:13.360 --> 0:02:16.400 In some cases, scarlet dust may be a contributing factor. 0:02:17.000 --> 0:02:20.200 Servini said. Many of the historic blood snows of Europe 0:02:20.200 --> 0:02:23.519 are associated with moisture mixing with red Saharan dust that's 0:02:23.560 --> 0:02:26.640 blown northward into Europe, which then falls out as either 0:02:26.720 --> 0:02:29.959 red rain or snow. But it turns out that more 0:02:30.000 --> 0:02:33.079 often than not, red snow is the product of algae, 0:02:33.600 --> 0:02:36.840 and as scientists have learned recently, the stuff is also 0:02:36.919 --> 0:02:40.639 contributing to climate change. We've known for some time now 0:02:40.680 --> 0:02:43.280 that red or pink snow is generally caused by select 0:02:43.360 --> 0:02:47.720 types of green algae, including these species Clematomonas novellis. These 0:02:47.800 --> 0:02:50.880 life forms live in high altitude snow fields around the world. 0:02:51.280 --> 0:02:54.200 Although they're technically green in color, the algae produce a 0:02:54.240 --> 0:02:57.560 red pigment during the warm seasons. Doing so helps protect 0:02:57.600 --> 0:03:01.359 the organisms from excessive solar radiation. We also spoke with 0:03:01.400 --> 0:03:05.040 biologist Arwin Edwards, a research fellow at eberyest With University 0:03:05.080 --> 0:03:08.000 in Wales. He said, I think of the red pigment 0:03:08.120 --> 0:03:11.160 as a sunscreen. He explained the life cycle of this 0:03:11.320 --> 0:03:14.800 and related types of algae. During the winter, the organisms 0:03:14.840 --> 0:03:17.639 go dormant. Once spring arrives, they make their way toward 0:03:17.720 --> 0:03:20.280 the surface of the snow and then bloom. But in 0:03:20.360 --> 0:03:23.040 order to grow, the life forms need liquid water in 0:03:23.080 --> 0:03:26.240 the form of wet snow in order to photosynthesize. This 0:03:26.360 --> 0:03:28.639 is another reason why the red pigment is so useful. 0:03:29.560 --> 0:03:32.600 Dark colored objects absorb more heat than light colored ones. 0:03:33.120 --> 0:03:36.200 In snowy field where clematomotis is present, you'll find dense 0:03:36.200 --> 0:03:39.920 communities of the microorganisms. A single millimeter that's point zero 0:03:40.000 --> 0:03:43.120 three inches of snow can contain five hundred thousand of 0:03:43.120 --> 0:03:45.440 these life forms. So in a large cluster of the 0:03:45.440 --> 0:03:48.720 algae starts to release red pigment and mass, they darken 0:03:48.760 --> 0:03:51.200 the snow they're living in. As a result, the snow 0:03:51.240 --> 0:03:54.640 itself adopts a pinkish look. It also begins to melt. 0:03:55.840 --> 0:03:59.640 So is this a cause for concern? In twice sixteen, 0:03:59.760 --> 0:04:02.600 each tonal Nature published a report written under the leadership 0:04:02.600 --> 0:04:06.000 of Stephanie Lutts, then a scientist at the University of Leeds. 0:04:06.120 --> 0:04:08.840 Edwards was one of her co authors. After looking at 0:04:08.880 --> 0:04:12.360 forty samples of the scarlet material from glaciers in Iceland, Norway, 0:04:12.480 --> 0:04:17.520 Greenland and Sweden, the researchers reached a harrowing conclusion. Edwards said, 0:04:17.880 --> 0:04:20.000 our paper is one of the first of several which 0:04:20.000 --> 0:04:23.760 have identified a five to fiftcent acceleration of glacier melting 0:04:23.839 --> 0:04:26.679 rates as a result of algae on the glacier surface, 0:04:27.000 --> 0:04:31.640 a biological darkening effect. Put another way, glacial snow melts 0:04:31.760 --> 0:04:35.280 five to fifteen percent more rapidly when Clementomonus or similar 0:04:35.279 --> 0:04:38.360 types of algae are present, and that's not good news. 0:04:39.400 --> 0:04:43.360 University of Bristol glaciologist Alejandra Anisio was a co author 0:04:43.440 --> 0:04:47.000 on that Nature paper. Summing up the problem in an 0:04:47.000 --> 0:04:50.960 email exchange, he said, basically, because of the darker coloration 0:04:51.000 --> 0:04:53.400 of snow with the presence of the algae, the snow 0:04:53.440 --> 0:04:56.760 absorbs more of the solar radiation, which increases pretension of 0:04:56.839 --> 0:04:59.760 heat and melting of the snow. The process is not 0:04:59.839 --> 0:05:02.360 in significant and must be taken into account if we 0:05:02.400 --> 0:05:05.160 want to understand how fast glaciers and ice sheets will 0:05:05.160 --> 0:05:08.719 melt with global warming. Also, there may be a self 0:05:08.720 --> 0:05:12.279 perpetuating feedback loop at work here. The red tinted algae 0:05:12.320 --> 0:05:14.719 melts snow, which enables more of the algae to grow, 0:05:14.920 --> 0:05:18.240 which leads to even more melted snow and so on. 0:05:19.160 --> 0:05:21.760 But let's shift gears for a moment and talk about 0:05:21.760 --> 0:05:25.760 one of the red snow's weirdest qualities. It's scent. People 0:05:25.760 --> 0:05:28.680 who come across the algae laden snow sometimes report that 0:05:28.760 --> 0:05:32.159 it has a sweet, watermelon like scent. For the record, 0:05:32.279 --> 0:05:35.080 Edward says he's never detected the odor himself, but that 0:05:35.160 --> 0:05:38.640 it's probably the byproduct of those red pigments. Some popular 0:05:38.680 --> 0:05:41.559 science writers have also advised against eating red snow because 0:05:41.560 --> 0:05:44.880 it has been reported to cause gastric problems, perhaps due 0:05:44.920 --> 0:05:49.080 to the algae other decaying material or mineral dusts and 0:05:49.240 --> 0:05:52.680 snow can come in other colors as well. In January eighteen, 0:05:52.920 --> 0:05:56.480 Central Kazakhstan received a layer of black tinted snow. This 0:05:56.600 --> 0:05:59.640 may have been the result of industrial pollution. Additionally, there 0:05:59.680 --> 0:06:03.120 are some types of algae that create yellowish snow. Of course, 0:06:03.160 --> 0:06:05.440 as any third grader or dog owner can tell you, 0:06:05.720 --> 0:06:14.160 that's not the only way to get yellow snow. Today's 0:06:14.200 --> 0:06:17.120 episode is based on the article the Amazing and Alarming 0:06:17.279 --> 0:06:20.159 science behind red Snow on how stuff Works dot com, 0:06:20.240 --> 0:06:23.440 written by Mark Mancini. Brainstuffs production of My Heart Radio 0:06:23.480 --> 0:06:25.440 in partnership with how Stuff Works dot com and it's 0:06:25.440 --> 0:06:28.360 produced by Tyler Clang. Four more podcasts from My Heart 0:06:28.440 --> 0:06:31.520 Radio visit the heart Radio app, Apple Podcasts, or wherever 0:06:31.560 --> 0:06:32.920 you listen to your favorite shows.